The most widely used tool for threat modeling is the Microsoft Threat Modeling Tool. It is available free of charge to all and can be downloaded from https://www.microsoft.com/en-in/download/details.aspx?id=49168.
Once downloaded and installed, the initial screen looks like this:
Click on Create A Model to get started with designing a new threat model, as shown in the following screenshot. You will be presented with a blank canvas to proceed with designing:
The right-hand pane, as shown in the following screenshot, ...
